It's a bit surreal that we gather and store information about our own bodies. The metrics are known values that you don't actually know. You apply two fingers to the opposite wrist in order to gather a heart rate, which is happening at your very core. You've been present for every breath you've taken, yet you have no idea how many there have been.

You need these interpreters called instruments to tell you what's going on, and secretaries called logs, or computers, to remember. As we exercise, or eat, or play, or whatever, we have ways to gather many of these statistics, even though there's a computer that's already done that work. We just haven't quite decrypted its language.

So we fasten fitness bands to our wrists, wrap them around our waist or clip them to our belts to remember steps, heart rate, stairs climbed, calories burned, hours slept and so on. We're told that soon sensors will be spitting information from every corner of our lives, analyzing and altering society's habits for the better. Fitness should be one of the beneficiaries.

To give you perspective on my perspective, I've been blessed with good health and also take a strong love in all things biological. My hopes for the future wouldn't quite jibe with Ray Kurzweil, but I don't rule out nerves and nanobots having a lot more in common down the line. To grab a snapshot of where we are now, I spent some time with the Fitbit Force (and some other bands, but not nearly as much). "Reviewing" this particular model is immaterial - how did it fit into my life?

The first thing I noticed is that I stopped noticing it. That's not necessarily a positive testament. I didn't really check the accompanying app that much. In fact, the only times I really thought about the black rubber band was before and after a shower - it's not waterproof - and occasionally in the middle of the night when some sleep position would cause it to strangle my hand.

So I started to wonder why, exactly, I stopped paying attention. I exercise and love math and statistics - shouldn't I be obsessing here?

Say what

Some of it has to do with my routines. I talked with Jill Harris, who runs Informed Body, a Pilates studio in Hayes Valley, who noted that she doesn't have much use for tracking bands. "Technology isn't going to tell (my clients) 'Oh, your abs are stronger.' "

Allow for the futurist's "yet," but there is some truth there. For anaerobic exercise, so far, we still manually log our reps or even time spent in downward dog. The instruments to do so automatically aren't quite there yet. Bands, so far, are really more for the aerobic information.

Part of me also wonders if my data apathy was a product of exercise getting along just fine without these metrics for decades. Our brains haven't been trained in how to consume "steps taken," to put them in perspective. What does taking 11,293 steps really mean?

For many, though, that answer is simply "a goal." I chatted with Amy Frey, who directs the health and wellness programs at the YMCA on the Embarcadero, to get her take on how she's seen fitness, in general, change over the past few years as these bands have caught on. Plenty of folks strive for the daily challenge of hitting their 10,000 steps, she says, and no doubt that's a positive.

But she also, perhaps unintentionally, damned fitness bands with faint praise a few times, calling them "an awareness tool." The point being that they weren't quite integral to people's fitness - more reminders that people should do something to break a sweat.

She also noted that bands' measurements usually examine the production of our body - floors climbed, steps taken, miles ran - which should never be confused for paying attention to our bodies themselves.

Future tense

We can develop a fun - and bizarre - sense of the future when thinking about cutting out the middleman: the band itself, or the act of entering data.

For instance, many apps log your food intake, but after about the second or third meal of matching results for a particular ham sandwich (without mustard, but with cheese, and I think the bread was wholegrain), the task becomes decidedly onerous. It is, of course, very interesting data - there's just no easy way to transfer it from the plate to my phone yet.

I couldn't help but imagine something like Google Goggles, the company's search-by-image feature, filling in the blanks. Take a picture of the meal (seems everyone's doing this anyway) and whamo, that ham sandwich in its 323-calorie glory populates the app. Or maybe the restaurant's computer system knows the calories and just beams them to my phone when I get the bill. Or maybe there's a tiny sensor pinned to the inside of my aorta that takes continued readings of my blood glucose levels and feeds them to a - OK, I'll stop. You get the picture.

Whatever form it takes, we know fads like the diet of the year, trendy exercise programs and various flashy statistics come and go. There isn't much research on whether health trackers have started to slim down that average American. There is an argument to be made that these bands are primarily used by those obsessed with fitness anyway.

And that's great. But the hope is that fitness bands are also getting people off the couch who wouldn't have otherwise. A fitness band may be Version 2.0 of a gym membership on New Year's. We'll see.

App companies are trying to improve "engagement" by "socializing" the data: I can compare metrics with friends. Competition is certainly an important motivator. But at the same time, if someone were to continue losing, they might stop playing. And the very out of shape may be hesitant to get in the game at all. We'll have to wait a while for anything compelling, but the research on these bands should prove illuminating.